Red triangle and E-brake issues

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Prius_newb89, Jun 14, 2025 at 4:24 PM.

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  1. Prius_newb89

    Prius_newb89 Junior Member

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    I have a 2008 prius with about 140k miles and am having new problems I replaced the inverter pump less than a year ago. When it is hot outside Im still getting the PA093 (inverter pump) code. I have checked the reservoir and can see the coolant flowing and the Battery temps go down when I'm driving. Is there some kind of sensor I should be checking that has gone bad?
    Second and most recent issue. In conjunction with the inverter pump code, the emergency break (red break light on the dash) will come on along with a nonstop ringing. When this happens I have to push the break much harder to stop and after a while the power steering will go out and the car will kill all power to the wheels completely. Not fun on hills. If I clear the code and turn the car off for a few minutes it will drive normally again. I check thr break/PS fluid, levels are normal. This only seems to be an issue in hot weather 80+ degrees. And diagnostic help is greatly appreciated!
     
    #1 Prius_newb89, Jun 14, 2025 at 4:24 PM
  2. dolj

    dolj Senior Member

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    Check that the fans behind the radiator are working correctly.

    There are two INF codes associated with P0A93, 346 and 347, which pinpoint the problem to coolant pump malfunctioning (346) and cooling fans malfunctioning (347).

    A higher percentage of the time, it is the inverter coolant pump that has failed, but not always, so you cannot say P0A93 means the pump has failed.
     
    #2 dolj, Jun 15, 2025 at 12:29 AM
  3. ChapmanF

    ChapmanF Senior Member

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    ^^ Further to that, this is an example where using "folk translations" of a trouble code, like "PA093 (inverter pump) code", can slow you down. When you use the actual fortune cookie "Inverter Cooling System Performance" for P0A93, at least it reminds you to think about other possibilities besides the pump. It's not a "go change this pump" code, it's an "electronics getting too hot, go figure out why" code.
     
    #3 ChapmanF, Jun 15, 2025 at 7:16 AM
    Brian1954 likes this.
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